Viessmann 100-W B1KA Fuel Consumption

[notretiredyet]

Hello,

I have a Vitodens 100-W B1KA Combi boiler installed in a new build. In the first 4 months of use the boiler has burned on average 500 litres/month. Not sure what I was expecting but that seems high. Any dieas of what I can do to improve it? I've eliminated any ramping by keeping the zone settings consistent. I've also adjusted the heat curve down to 0.6 - to reduce the max water temperature.

The boiler is heating 2 concrete floors (basement and main level), approximately 2200 sq ft in total. The basement is ICF construction (approximately R-40), with 3.5" of EPS foam under slab (no windows or door). The main level walls and roof are SIP construction (apprx R-50). Windows all triple pain - as best as I can do - can't afford those Euro tilt/turn high efficiency types 🙂.

 

[dr911t]

I have the same combi boiler (from 2017) with an underfloor heating on a concrete screed only (no radiators) and domestic hot water. 1300sq ft. Mild winter uses around 8-10m3 of natural gas per day.

 

[John.g]

Not a whole lot of difference in actual consumptions, 500 lires of LPG contains = 3550 kwh. cons/day ~ 118kwh. Natgas 10M3/day=~110kwh. but BC house is twice the size.